ch_3

//1
val n = 10
val range = 0 until n
var a =  new Array[Int](n)

for (i <- 0 until n) a(i) = range(rnd.nextInt(range.length))

//2
var a = Array(1, 2, 3, 4, 5)

for (i <- 0 until a.length) {
  if (i % 2 == 0 && i < a.length - 1) {
    val tmp = a(i)
    a(i) = a(i + 1)
    a(i + 1) = tmp
  }
}

//3
val a = Array(1, 2, 3, 4, 5)

var newArray = for (i <- 0 until a.length) yield {
  if (i % 2 == 0) {
    if (i == a.length - 1) {
      a(i)
    } else {
      a(i+1)
    }
  } else {
    a(i-1)
  }
}

//waaay neater approach from SO:
val betterWay = a.grouped(2).flatMap(_.reverse).toArray

//4 nifty...
val a = Array(1, 2, 3, 4, 5, 0, -1, 4, 0, -5, -2, -9, 0)
val sorted = a.filter(x => x > 0) ++ a.filter(x => x <= 0)

//5 nifty...
val a = Array(2.0, 3.5, 4.6, 91.65, 13.124)
val avg = a.sum / a.length

//6 pretty sure I missed the point here
val a = Array(1, 2, 3, 4, 5, 0, -1, 4, 0, -5, -2, -9, 0)
val aDescending = a.sortWith(_ > _)

import collection.mutable.ArrayBuffer
val a = ArrayBuffer(1, 2, 3, 4, 5, 0, -1, 4, 0, -5, -2, -9, 0)
val aDescending = a.sortWith(_ > _)

//7
val a = Array(1, 2, 3, 4, 5, 0, -1, 4, 0, -5, -2, -9, 0)
val distinct = a.distinct

//8
import collection.mutable.ArrayBuffer
val a = ArrayBuffer(1, 2, 3, 4, 5, 0, -1, 4, 0, -5, -2, -9, 0)
var indexes = for (i <- 0 until a.size if a(i) < 0) yield i
indexes = indexes.drop(1)
for (j <- (0 until indexes.size).reverse) a.remove(indexes(j))

//9
import java.util.TimeZone
var timezones = TimeZone.getAvailableIDs()
timezones = timezones.filter(timezone => timezone.indexOf("America/") == 0)
timezones = timezones.map(timezone => timezone.replace("America/", ""))
timezones = timezones.sortWith(_ < _)

//10
import java.awt.datatransfer._
import collection.mutable.ArrayBuffer
import scala.collection.JavaConversions._

val flavors = SystemFlavorMap.getDefaultFlavorMap().asInstanceOf[SystemFlavorMap]
val buffer = asScalaBuffer(flavors.getNativesForFlavor(DataFlavor.imageFlavor))